1. Field of the Invention
The present invention relates to a digital TV, and in particular to a caption display device for a digital TV and a method thereof.
2. Description of the Background Art
Currently, a caption device for an NTSC analog TV displays a caption of a predetermined size at a predetermined position of a screen (as transmitted from a broadcasting station).
That is, when an image screen and a caption are displayed at the same time, the caption partially covers the image, and thus the hidden image cannot be seen. A caption window is not defined in the analog caption. Accordingly, there is no solution although the caption of a predetermined size and position transmitted from the broadcasting station covers a part of the image screen.
In the case of a digital TV broadcasting caption that will be serviced sooner or later, the caption windows of a different size are supported. But when a few caption windows are simultaneously displayed on the screen, the image screen is hidden in proportion to the caption windows. As a result, a part of the TV image screen cannot be seen.
As described above, the background of the caption text and the caption window partially cover the TV image screen. In this regard, the users strongly demand service improvements.
Accordingly, an object of the present invention is to provide a caption display device for a digital TV enabling the users to adjust density of a caption window displayed on a screen of the digital TV.
In order to achieve the above-described object of the present invention, there is provided a caption display device for a digital TV including: a video decoder unit for decoding an inputted MPEG II transport stream, and separately outputting a user data for caption and an MPEG II video data; an ATV caption command decoder unit for decoding the user data separated in the video decoder unit, and outputting a data having a caption command and a caption text; a user interactive control unit for sensing an interactive data inputted from the user; a caption control unit for outputting a caption text background control command in order to control a blending rate by using the user interactive signal outputted from the user interactive control unit; a blending unit for blending the ATV caption data separated in the ATV caption command decoder unit with the caption text background control command outputted from the caption control unit, and outputting a Muxing data; a video combining unit for combining and outputting the MPEG II video data separated in the video decoder unit and the Muxing data outputted from the blending unit; and a video data processing unit for processing and outputting a color blending according to the signal outputted from the video combining unit.